The head of Tunisia's ruling Islamist party Ennahda called on Thursday for national consensus at the launch of its first congress at home in 24 years, held at a time of political and religious tensions.

"We want to convey a message from this congress, this congress of a union of the Tunisian people. We are a united people," Rached Ghannouchi told around 10,000 supporters.

"I want to assure the people that the country is in good hands," he said.

"This country needs a national consensus. We call for national reconciliation," said Ghannouchi, playing down the crises that have shaken Tunisia and its ruling coalition as "normal" for a post-revolutionary state.

"In Tunisia, all movements can cohabit," he said.

The three-day gathering is being held at a congress centre in Al Karm, a Tunis suburb that in the past hosted meetings of toppled president Zine El Abidine Ben Ali's now disbanded party.

Ennahda (Renaissance) now dominates the government along with centre-left parties the Congress for the Republic (CPR) and Ettakatol, which won 33 percent of the seats in the assembly.

"We must combat dictatorship, whether it be in the name of religion or of modernity," said Ettakatol chief Mustapha Ben Jafaar in his speech.

"Our future is in our hands to form a civil society and set up a civil republican regime for a modern state which guards the identity of the Arab-Muslim people," said the former opposition figure.

Some 25,000-30,000 people are to attend the congress, the party's first since it came to power following Ben Ali's ouster in protests that touched off the 2011 Arab Spring.

Among the guests is Khaled Meshaal, political chief of the Palestinian Islamist movement Hamas, which rules the Gaza Strip.

"We must build an Arab-Muslim strategy to liberate Palestine and turn the page on negotiations" with Israel, he said in a speech.

"The Palestinians aren't selfish, so take your time to get through this difficult transitory period -- it is your right," Meshaal said, adding: "The only way to liberate Palestine is the struggle."

Conference participants also showed their support for the uprising in Syria. "Bashar, get out!" they chanted, referring to President Bashar al-Assad.

About 1,100 delegates will have to determine Ennahda's position on political alliances, as the dominant partner in the government coalition.

The congress will also seek to reconcile different trends within the party, between moderates and more radical ideologues, with founding leader Ghannouchi expected to keep his post.

Established in June 1981 by Ghannouchi and a group of intellectuals inspired by Egypt's Muslim Brotherhood, Ennahda was banned by Ben Ali after a major electoral success in 1989, and its leaders jailed or forced into exile.

Ghannouchi returned in January 2011 after 20 years in London.

Ennahda won Tunisia's first post-uprising poll, in October, taking 41 percent of the seats in the National Constituent Assembly, the interim body tasked with drafting a new constitution and preparing fresh elections, due in March 2013.

Ennahda said in March that Islamic sharia would not be inscribed in Tunisian basic law, much to the relief of its coalition partners which feared the Islamist majority in parliament might open the door to a theocracy.

"Finally, after 40 years of prison and exile, we are reunited," Ennahda official Riadh Chaibi told the crowd in Al Karm, to roars of approval. "We pay tribute to the martyrs of the movement."

The government faces wide-ranging challenges.

Tunisia's latest political crisis came last month, when Prime Minister Hamadi Jebali ignored President Moncef Marzouki's opposition to the extradition of former Libyan premier Baghdadi al-Mahmudi.

The row between Jebali and CPR member Marzouki exposed the uneasy nature of the governing coalition.

Tunisia is also regularly shaken by social unrest.

The party aims to reduce unemployment, a driving factor behind the revolution, to 8.5 percent by 2016 from around 19 percent now, but the economy is still struggling.

Ennahda has also struggled to clarify its line on Salafists -- hardline Islamists who have grown more confident post-revolution -- with recent violence sparking criticism that it has done too little to stop them.

Salafists went on the rampage in mid-June after taking issue with art works at a Tunis exhibition they deemed offensive to Islam.